Apart from Heinlein, I can think of Tiptree, Varley, and Lee (Tanith) off the top of my head. There are some anthologies of queer sf, and a couple of the stories in those books are trans-related. And I have read a number of works that are pretty much one-offs--stories whose titles and authors I don't remember, unfortunately. But as I said, I haven't read much of the stuff that's come out in the last couple of decades.
I wrote a real-world-based sf novel with an FTM theme, but I wrote it for myself, not for publication. And the FTM theme doesn't come into the first book much. Not that Robin would be interested...I really don't think any of this stuff, published or not, even approaches what Robin is asking about.